Information transmission method and device

ABSTRACT

Embodiments of the present invention provide an information transmission method and device. The method includes: reporting, by a UE, a CQI value to an eNB; receiving, by the UE, an MCS value sent by the eNB, where the MCS value is determined by the eNB according to the CQI value; and receiving, by the UE, PDSCH data according to the MCS value, where the CQI value and the MCS value are determined according to a second set of tables, where a modulation scheme that can be supported by the second set of tables is higher than 64QAM. The embodiments of the present invention can improve system performance and reduce waste of feedback resources.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application a continuation of U.S. patent application Ser. No. 14/474,532, filed on Sep. 2, 2014, which is a is a continuation of International Application No. PCT/CN2013/071684, filed on Feb. 20, 2013, which claims priority to Chinese Patent Application No. 201210054842.6, filed on Mar. 2, 2012, and all of the afore-mentioned patent applications are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to mobile communications technologies, and in particular, to an information transmission method and device.

BACKGROUND

Currently, an auto negotiation process of a physical downlink shared channel (Physical Downlink Shared Channel, PDSCH) in a Long Term Evolution (Long Term Evolution, LTE) system is: A user equipment (User Equipment, UE) estimates channel information that is used to measure channel state information (Channel State Information, CSI); by using the estimated channel information, the UE calculates a signal to interference plus noise ratio (Signal to Interference plus Noise Ratio, SINR) based on an optimal rank indication (Rank Indication, RI) and/or a precoding matrix indication (Precoding Matrix Indication, PMI); the UE quantizes the calculated SINR into a 4-bit channel quality indicator (Channel Quality Indicator, CQI); the UE reports the CQI value to an evolved NodeB (evolution NodeB, eNB); the eNB allocates a modulation and coding scheme (Modulation and Coding Scheme, MCS) to the UE according to the CQI value reported by the UE and network conditions, where the MCS is used to indicate the modulation and coding scheme currently used by the PDSCH; and the UE receives PDSCH data according to the MCS. In the process of quantizing the SINR into the CQI, a main interval of the SINR is (−7 dB, 19.488 dB) , and SINRs outside the interval are processed in a saturation manner.

In a hotspot scenario such as a relay (Relay) or LTE hotspot improvements (LTE Hotspot Improvements, LTE-Hi) scenario, all SINR values obtained by the UE are large. For example, under certain conditions, almost 50% of SINR values of the UE are greater than 20 dB. However, because the SINR values greater than a maximum value of the main interval are processed in a saturation manner in the process of quantizing the SINR into the CQI, and an index of a CQI corresponding to an SINR in the saturation manner is 15, the UE at most can select only a modulation and coding scheme corresponding to the CQI whose index is 15, which restricts a terminal from selecting a higher modulation and coding scheme and affects system performance.

SUMMARY

Embodiments of the present invention provide an information transmission method and device to solve a problem that system performance is lower than expected in the prior art.

An embodiment of the present invention provides an information transmission method, including:

reporting, by a UE, a CQI value to an eNB;

receiving, by the UE, an MCS value sent by the eNB, where the MCS value is determined by the eNB according to the CQI value; and

receiving, by the UE, PDSCH data according to the MCS value,

where the CQI value and the MCS value are determined according to a second set of tables, where a modulation scheme that can be supported by the second set of tables is higher than 64QAM.

An embodiment of the present invention provides an information transmission device, including:

a first sending module, configured to report a CQI value to an eNB;

a first receiving module, configured to receive an MCS value sent by the eNB, where the MCS value is determined by the eNB according to the CQI value; and

a second receiving module, configured to receive PDSCH data according to the MCS value,

where the CQI value and the MCS value are determined according to a second set of tables, where a modulation scheme that can be supported by the second set of tables is higher than 64QAM.

From the foregoing technical solution, it can be learned that in the embodiments of the present invention, a set of CQI and MCS tables is reset so that the CQI and the MCS can support modulation schemes higher than 64QAM, therefore implementing support for higher modulation schemes, meeting requirements in a hotspot scenario and improving system performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowchart of an embodiment of an information transmission method according to the present invention;

FIG. 2 is a schematic flowchart of another embodiment of an information transmission method according to the present invention;

FIG. 3 is a curve of relationships between spectral efficiency and SINRs in different modulation schemes according to the present invention;

FIG. 4 is a schematic structural diagram of an embodiment of an information transmission device according to the present invention;

FIG. 5 is a schematic structural diagram of another embodiment of an information transmission device according to the present invention; and

FIG. 6 is a schematic structural diagram of another embodiment of an information transmission device according to the present invention.

DETAILED DESCRIPTION

FIG. 1 is a schematic flowchart of an embodiment of an information transmission method according to the present invention, including:

Step 11: A UE reports a CQI value to an eNB.

Step 12: The UE receives an MCS value sent by the eNB, where the MCS value is determined by the eNB according to the CQI value.

Step 13: The UE receives PDSCH data according to the MCS value, where the CQI value and the MCS value are determined according to a second set of tables, where a modulation scheme that can be supported by the second set of tables is higher than 64QAM.

For a better understanding of the present invention, the following first describes a CQI table and an MCS table in an existing protocol. Table 1 is a CQI table in the existing protocol, and Table 2 is an MCS table in the existing protocol.

TABLE 1 Code rate × Modulation 1024 Spectral CQI index scheme (code rate × efficiency (CQI index) (modulation) 1024) (efficiency) 0 Out of range (out of range) 1 QPSK 78 0.1523 2 QPSK 120 0.2344 3 QPSK 193 0.3770 4 QPSK 308 0.6016 5 QPSK 449 0.8770 6 QPSK 602 1.1758 7 16QAM 378 1.4766 8 16QAM 490 1.9141 9 16QAM 616 2.4063 10 64QAM 466 2.7305 11 64QAM 567 3.3223 12 64QAM 666 3.9023 13 64QAM 772 4.5234 14 64QAM 873 5.1152 15 64QAM 948 5.5547

TABLE 2 Modulation order Transport block size MSC index (modulation (transport block size, (MCS index) order) TBS) index (TBS index) I_(MCS) Q_(m) I_(TBS) 0 2 0 1 2 1 2 2 2 3 2 3 4 2 4 5 2 5 6 2 6 7 2 7 8 2 8 9 2 9 10 4 9 11 4 10 12 4 11 13 4 12 14 4 13 15 4 14 16 4 15 17 6 15 18 6 16 19 6 17 20 6 18 21 6 19 22 6 20 23 6 21 24 6 22 25 6 23 26 6 24 27 6 25 28 6 26 29 2 Reserved (reserved) 30 4 31 6

The numbers 2, 4 and 6 in the modulation orders in the foregoing MCS respectively denote the following modulation schemes: quadrature phase shift keying (Quadrature Phase Shift Keying, QPSK), 16 quadrature amplitude modulation (Quadrature Amplitude Modulation, QAM), and 64QAM.

It can be seen from Table 1 and Table 2 that the modulation schemes that can be supported by the CQI/MCS in the existing protocol are QPSK, 16QAM, and 64QAM, and the modulation scheme of the highest order is 64QAM.

In a hotspot scenario, an SINR is mostly high, and can sufficiently support a modulation scheme higher than 64QAM. However, according to an existing protocol manner, the highest supported modulation scheme is only 64QAM, which affects system performance.

In this embodiment of the present invention, requirements in the hotspot scenario are considered and a set of CQI/MCS tables is redesigned. To distinguish from the existing protocol, the existing CQI/MCS tables may be referred to as a first set of tables, and the tables redesigned in this embodiment of the present invention may be referred to as a second set of tables. The second set of tables in this embodiment of the present invention supports modulation schemes of higher orders, and support for 256QAM is used as an example in this embodiment of the present invention. Surely, if modulation schemes of higher order need to be supported, modulation schemes of even higher orders such as 1024QAM may be supported.

In specific implementation, a CQI table of a same size as that of an existing CQI table maybe used. In this case, values of a modulation scheme, a code rate and spectral efficiency corresponding to each CQI index in the CQI table need to be redesigned; or, the number of bits of the CQI may also be extended, for example, the CQI in the prior art is 4 bits, and the CQI in this embodiment of the present invention maybe designed as 5 bits, and therefore, there are 16 additional indexes more than the indexes of the existing CQI, and the additional part is used to denote 256QAM. For specific implementation, refer to subsequent embodiments.

FIG. 2 is a schematic flowchart of another embodiment of an information transmission method according to the present invention, including:

Step 21: A UE sends control signaling to an eNB, where the control signaling is used to indicate that the UE supports a second set of tables.

The UE may use a feature group indicator (feature Group Indicators, FGI) bit or another radio resource control (Radio Resource Control, RRC) command to notify the eNB that the UE supports the second set of tables.

Step 22: The eNB sends control signaling to the UE, where the control signaling is used to indicate use of the table.

After determining that the UE can support the second set of tables, the eNB may decide whether to use a first set of tables or the second set of tables according to actual network conditions.

For example, the eNB may determine to use the second set of tables if determining that the existing channel conditions are good, and specifically, if a reference signal received power (Reference Signal Received Power, RSRP) or reference signal received quality (Reference Signal Received Quality, RSRQ) that is obtained by means of measurement is greater than a set value. Alternatively, the eNB may determine to use the second set of tables if all CQI orders reported by the UE and received by the eNB in a set time are higher than a set order and data is continuously and correctly received. For example, if all CQI orders reported by the UE and received by the eNB in a set time T are 64QAM and data is continuously and correctly received, the eNB may determine that a modulation scheme of a higher order can be used, and therefore, determine to use the second set of tables.

If the eNB determines to use the second set of tables, control signaling that is used to indicate use of the second set of tables is specifically sent, and this case is used as an example in this embodiment. It can be understood that, when the eNB determines to use the first set of tables, after the eNB sends to the UE control signaling that is used to indicate use of the first set of tables, execution may be implemented according to the prior art.

Step 23: The UE determines a CQI value according to a second set of formats, and sends the CQI value to the eNB.

Step 24: The eNB determines an MCS value according to the second set of formats, and sends the MCS value to the UE.

Step 25: The UE receives PDSCH data according to the MCS value.

The CQI table in the second set of tables may be shown in Table 3, and the MCS table in the second set of tables may be shown in Table 4 or Table 5.

TABLE 3 Code rate × Modulation 1024 Spectral CQI index scheme (code rate × efficiency (CQI index) (modulation) 1024) (efficiency) 0 Out of range (out of range) 1 QPSK 75 0.1467 2 QPSK 294 0.5733 3 QPSK 724 1.4133 4 16QAM 423 1.6533 5 16QAM 587 2.2933 6 16QAM 764 2.9867 7 64QAM 573 3.3600 8 64QAM 655 3.8400 9 64QAM 728 4.2667 10 64QAM 801 4.6933 11 64QAM 874 5.1200 12 256QAM 696 5.4400 13 256QAM 778 6.0800 14 256QAM 860 6.7200 15 256QAM 942 7.3600

TABLE 4 Transport block size Modulation order (transport block MSC index (modulation size, TBS) index (TBS (MCS index) order) index) I_(MCS) Q_(m) I_(TBS) 0 2 0 1 2 1 2 2 2 3 2 3 4 2 4 5 4 5 6 4 6 7 4 7 8 4 8 9 4 9 10 4 10 11 6 11 12 6 12 13 6 13 14 6 14 15 6 15 16 6 16 17 6 17 18 6 18 19 6 19 20 6 20 21 8 21 22 8 22 23 8 23 24 8 24 25 8 25 26 8 26 27 8 27 28 2 Reserved (reserved) 29 4 30 6 31 8

TABLE 5 Transport block size Modulation order (transport block MSC index (modulation size, TBS) index (TBS (MCS index) order) index) I_(MCS) Q_(m) I_(TBS) 0 2 0 1 2 1 2 2 2 3 2 3 4 2 4 5 4 4 6 4 5 7 4 6 8 4 7 9 4 8 10 4 9 11 6 10 12 6 11 13 6 12 14 6 13 15 6 14 16 6 15 17 6 16 18 6 17 19 6 18 20 6 19 21 8 19 22 8 20 23 8 21 24 8 22 25 8 23 26 8 24 27 8 25 28 2 Reserved (reserved) 29 4 30 6 31 8

It can be seen from Table 3 that the CQI table in the second set of tables meets the following conditions:

(1) In any modulation scheme whose modulation order is higher than 2, differences between two adjacent spectral efficiency values are approximately equal, where a being approximately equal to b means that an absolute value of a difference between a and b is less than a set value, where the set value may be 0.2.

For example, corresponding to 16QAM, spectral efficiency is 1.6533, 2.2933, and 2.9867 respectively, and 2.2933−1.6533 is approximately equal to 2.9867−2.2933.

(2) A difference between spectral efficiency values that correspond to two adjacent modulation schemes respectively is less than a difference between any two adjacent spectral efficiency values in a single modulation scheme in the two modulation schemes.

For example, corresponding to adjacent QPSK and 16QAM, the corresponding spectral efficiency is 1.4133 and 1.6533 respectively, and 1.6533−1.4133 is less than 2.2933−1.6533, and is also less than 2.9867−2.2933.

Values in the CQI table that meets the foregoing conditions may be obtained in the following manner:

determining a curve of relationships between an SINR and spectral efficiency in each modulation scheme.

The spectral efficiency is defined as efficiency of correctly transmitting bits of each modulation symbol, and may be denoted by:

${\eta = {\frac{M}{N} \times Q_{mod}}},$

where M is the number of transmitted bits, N is the number of bits after encoding and rate matching are performed, Q_(mod) is an modulation order, and the modulation order of QPSK is 2. The modulation order of 16QAM is 4 . . . .

The design is based on scheduling of 4 RBs. The number N of bits that can be transmitted in the 4 RBs is obtained in the following manner:

1 subframe (subframe) has 14 OFDM symbols, and one of the OFDMs is reserved for a PDCCH, and the number of available OFDMs is 13.

One RB has 12 REs, and the number of valid REs in one RB of one subframe is 12×13=156.

4 RBs have 4×156=624 valid REs.

For QPSK modulation, the number (N) of encoded bits is 624×2=1248; and, for 16QAM, there are 624×4 bits, and so on. By now, N can be obtained.

The number (M) of original bits transmitted in the 4 RBs is obtained by searching a table according to a TBS allowed by QPP. For details, see the following table:

i K f₁ f₂ 1 40 3 10 2 48 7 12 3 56 19 42 4 64 7 16 5 72 7 18 6 80 11 20 7 88 5 22 8 96 11 24 9 104 7 26 10 112 41 84 11 120 103 90 12 128 15 32 13 136 9 34 14 144 17 108 15 152 9 38 16 160 21 120 17 168 101 84 18 176 21 44 19 184 57 46 20 192 23 48 21 200 13 50 22 208 27 52 23 216 11 36 24 224 27 56 25 232 85 58 26 240 29 60 27 248 33 62 28 256 15 32 29 264 17 198 30 272 33 68 31 280 103 210 32 288 19 36 33 296 19 74 34 304 37 76 35 312 19 78 36 320 21 120 37 328 21 82 38 336 115 84 39 344 193 86 40 352 21 44 41 360 133 90 42 368 81 46 43 376 45 94 44 384 23 48 45 392 243 98 46 400 151 40 47 408 155 102 48 416 25 52 49 424 51 106 50 432 47 72 51 440 91 110 52 448 29 168 53 456 29 114 54 464 247 58 55 472 29 118 56 480 89 180 57 488 91 122 58 496 157 62 59 504 55 84 60 512 31 64 61 528 17 66 62 544 35 68 63 560 227 420 64 576 65 96 65 592 19 74 66 608 37 76 67 624 41 234 68 640 39 80 69 656 185 82 70 672 43 252 71 688 21 86 72 704 155 44 73 720 79 120 74 736 139 92 75 752 23 94 76 768 217 48 77 784 25 98 78 800 17 80 79 816 127 102 80 832 25 52 81 848 239 106 82 864 17 48 83 880 137 110 84 896 215 112 85 912 29 114 86 928 15 58 87 944 147 118 88 960 29 60 89 976 59 122 90 992 65 124 91 1008 55 84 92 1024 31 64 93 1056 17 66 94 1088 171 204 95 1120 67 140 96 1152 35 72 97 1184 19 74 98 1216 39 76 99 1248 19 78 100 1280 199 240 101 1312 21 82 102 1344 211 252 103 1376 21 86 104 1408 43 88 105 1440 149 60 106 1472 45 92 107 1504 49 846 108 1536 71 48 109 1568 13 28 110 1600 17 80 111 1632 25 102 112 1664 183 104 113 1696 55 954 114 1728 127 96 115 1760 27 110 116 1792 29 112 117 1824 29 114 118 1856 57 116 119 1888 45 354 120 1920 31 120 121 1952 59 610 122 1984 185 124 123 2016 113 420 124 2048 31 64 125 2112 17 66 126 2176 171 136 127 2240 209 420 128 2304 253 216 129 2368 367 444 130 2432 265 456 131 2496 181 468 132 2560 39 80 133 2624 27 164 134 2688 127 504 135 2752 143 172 136 2816 43 88 137 2880 29 300 138 2944 45 92 139 3008 157 188 140 3072 47 96 141 3136 13 28 142 3200 111 240 143 3264 443 204 144 3328 51 104 145 3392 51 212 146 3456 451 192 147 3520 257 220 148 3584 57 336 149 3648 313 228 150 3712 271 232 151 3776 179 236 152 3840 331 120 153 3904 363 244 154 3968 375 248 155 4032 127 168 156 4096 31 64 157 4160 33 130 158 4224 43 264 159 4288 33 134 160 4352 477 408 161 4416 35 138 162 4480 233 280 163 4544 357 142 164 4608 337 480 165 4672 37 146 166 4736 71 444 167 4800 71 120 168 4864 37 152 169 4928 39 462 170 4992 127 234 171 5056 39 158 172 5120 39 80 173 5184 31 96 174 5248 113 902 175 5312 41 166 176 5376 251 336 177 5440 43 170 178 5504 21 86 179 5568 43 174 180 5632 45 176 181 5696 45 178 182 5760 161 120 183 5824 89 182 184 5888 323 184 185 5952 47 186 186 6016 23 94 187 6080 47 190 188 6144 263 480

M is K in the foregoing table. By now, M can be obtained.

After M and N are obtained, spectral efficiency can be obtained.

A TBS in each modulation scheme with a code rate that falls within an interval [0, 1] is selected. In AWGN, the TBS is used to emulate a minimum SINR required when a BLER is 10%. By now, the SINR can be obtained.

By using the SINR and the spectral efficiency, a curve of relationships is obtained.

Curves of relationships between spectral efficiency and SINRs in different modulation schemes, which are obtained by means of the foregoing emulation, may be shown in Table 3. Referring to FIG. 3, four curves from the bottom up correspond to QPSK, 16QAM, 64QAM, and 256QAM respectively. SINR values and spectral efficiency values at an intersection of two curves are (4.5 dB, 1.45), (12.5 dB, 3.5), and (19.2, 5.5) respectively.

(2) According to the curve of relationships corresponding to each modulation scheme, a value of each item in the CQI corresponding to each modulation scheme is obtained.

A certain number of points may be selected for each modulation scheme. On the curve of relationships corresponding to the modulation scheme, the spectral efficiency corresponding to the selected points is obtained. The value of the obtained spectral efficiency is the value of spectral efficiency in Table 3. The value of the spectral efficiency is divided by the modulation order to obtain a code rate, and then the code rate is multiplied by 1024 to obtain the value of code rate ×1024 in Table 3, where the modulation order of QPSK is 2, the modulation order of 16QAM is 4, the modulation order of 64QAM is 6, and the modulation order of 256QAM is 8.

The points selected in each of the modulation schemes meet the following conditions:

(1) When the SINR is less than a set value, the points are selected in an equal-SINR manner; and, when the SINR is greater than or equal to the set value, the points are selected in an equal-spectral-efficiency manner.

In this embodiment, the set value is 4.5 dB, and therefore, for the QPSK scheme, the points are selected in an equal-SINR manner; and, for 16QAM, 64QAM, and 256QAM, the points are selected in an equal-spectral-efficiency manner. It can be understood that because M has a selection range, a point obtained in the equal-spectral-efficiency manner or the equal-SINR manner is a point from which a value can be obtained and which is closest to the point obtained in the equal-SINR manner or the equal-spectral-efficiency manner.

In addition, in this embodiment, to ensure coverage, the CQI table still includes the corresponding modulation scheme when the SINR is small. However, to avoid using excessive CQI indexes to denote the modulation scheme when the SINR is small, the number of the corresponding modulation schemes when the SINR is small is reduced in this embodiment. For example, Table 1 is compared with Table 3 and it can be seen that the number of QPSK modulation schemes used in this embodiment is less than the number of QPSK modulation schemes used in the prior art.

(2) In a set range of an intersection of the curves of relationships corresponding to the two modulation schemes, a CQI index is selected, the modulation scheme corresponding to the selected CQI index is a higher-order modulation scheme in the two modulation schemes, and a difference between the spectral efficiency corresponding to the selected CQI index and maximum spectral efficiency in the other modulation scheme in the two modulation schemes is less than a difference between spectral efficiency values corresponding to any two CQI indexes in the higher-order modulation scheme.

The set range may be within a range of 0.5 dB near the intersection. For example, the SINR value at the intersection of QPSK and 16QAM is 4.5 dB, and therefore, a CQI index needs to be set in a range of (4.5−0.5, 4.5+0.5), and the modulation scheme corresponding to the index is the higher-order modulation scheme. That is, the corresponding modulation scheme is 16QAM. A value of spectral efficiency and a value of a code rate are obtained according to a curve of relationships corresponding to 16QAM.

Referring to Table 3, a difference between spectral efficiency corresponding to a CQI whose index is 4 and spectral efficiency corresponding to a CQI whose index is 3 is less than a difference between any two of spectral efficiency values corresponding to CQIs whose indexes are 4, 5, and 6.

After the CQI table is determined in the foregoing manner, the MCS table includes:

(1) all modulation schemes included in the CQI table;

for example, values corresponding to QPSK, 16QAM, 64QAM, and 256QAM in Table 3 are 3, 3, 5, and 4 respectively, and therefore, a modulation scheme in Table 4 corresponding to the 4 includes at least 3, 3, 5, and 4 values; and

(2) values obtained by performing interpolation for the modulation schemes included in the CQI table.

For example, there are 3 points corresponding to QPSK, and 2 points are obtained after interpolation is performed on the 3 points. The interpolation may specifically be equal-interval interpolation. For example, equal-SINR-interval interpolation is used for QPSK, and equal-spectral-efficiency-interval interpolation is used for 16QAM, 64QAM, and 256QAM.

After the interpolation, the MCS table includes the modulation scheme itself and the values after the interpolation, in which at least 3+2=5 values correspond to QPSK. Similarly, in the MCS table, there are at least 3+2=5 values corresponding to 16QAM, there are 5+4=9 values corresponding to 64QAM, and there are 4+3=7 values corresponding to 256QAM.

Because there are 28 valid values in the MCS table, the number of values after the interpolation is 5+5+9+7=26, and values corresponding to two MSC indexes remain. The remaining values of the two MCS indexes may be obtained by performing extrapolation or by selecting a TBS that is the same as that of another adjacent modulation scheme.

In a manner in which extrapolation is used, for example, referring to Table 4, after extrapolation is performed for 16QAM and QPSK, an MCS index corresponding to 16QAM is obtained; and, after extrapolation is performed for 64QAM and 256QAM, an MCS index corresponding to 64QAM is obtained.

In a manner in which a same TBS is used, for example, referring to Table 5, the TBS with an index of 5 and a modulation scheme of 16QAM is the same as the TBS with an index of 4 and a modulation scheme of QPSK; and the TBS with an index of 20 and a modulation scheme of 64QAM is the same as the TBS with an index of 21 and a modulation scheme of 256QAM.

By means of the foregoing determining principles, a type of the second set of tables may be obtained, such as Table 3 and Table 4, or Table 3 and Table 5. It can be seen from the foregoing tables that the second set of tables can support higher modulation schemes, and specifically can further support 256QAM. For example, when spectral efficiency is approximately 5.5, it can be learned from Table 3 that the used modulation scheme is 256QAM, but in the existing protocol, 64QAM is used. Therefore, this embodiment can support higher-order modulation schemes and improve system performance.

In addition, the number of CQI indexes in the CQI table in the second set of tables is the same as that in the CQI table in the first set of tables. Likewise, the number of MCS indexes in the MCS table in the second set of tables is the same as that in the MCS table in the first set of tables. Therefore, this embodiment is compatible with the existing protocol. Specifically, for the MCS table, because 4 modulation schemes are supported in this embodiment, 4 bits are required in the reserved part of the MCS table. The reserved part may be an MCS index number used for hybrid automatic repeat request (Hybrid Automatic Repeat Request, HARQ) retransmission.

The number of indexes in the second set of tables used in the foregoing embodiment is the same as that in the existing first set of tables. Optionally, the present invention gives another embodiment. In this embodiment, different from the existing CQI that occupies 4 bits, the CQI in this embodiment occupies 5 bits, and therefore, the number of CQI indexes is 32, but the existing number of CQI indexes is 16. In this case, the additional index entries may be used to denote 256QAM.

In a new CQI table, N index numbers are reserved for other signaling notification, where N=Nmodu−1, and Nmodu is the number of supported modulation schemes.

In this case, a size of the MCS table may be the same as that in the prior art, but higher modulation schemes are supported.

In this embodiment, a higher-order modulation scheme can be supported by using the second set of tables; and, with the QPSK modulation scheme still included, coverage is sufficiently considered. Compared with the prior art, this embodiment reduces values corresponding to QPSK, which can reduce waste of feedback overhead. By selecting a smaller difference between spectral efficiency values in two adjacent modulation schemes, transition between the two modulation schemes is more stable. The corresponding value is obtained for the higher-order modulation scheme in an equal-spectral-efficiency manner, which can improve system performance smoothly.

FIG. 4 is a schematic structural diagram of an embodiment of an information transmission device according to the present invention. The device may be a UE. The device includes a first sending module 41, a first receiving module 42, and a second receiving module 43. The first sending module 41 is configured to report a CQI value to an eNB; the first receiving module 42 is configured to receive an MCS value sent by the eNB, where the MCS value is determined by the eNB according to the CQI value; and the second receiving module 43 is configured to receive PDSCH data according to the MCS value, where the CQI value and the MCS value are determined according to a second set of tables, where a modulation scheme supported by the second set of tables is higher than 64QAM.

Optionally, referring to FIG. 5, the device may further include a second sending module 51 and a third receiving module 52. The second sending module 51 is configured to send control signaling to the eNB, where the control signaling is used to indicate that the device supports the second set of tables; and the third receiving module 52 is configured to receive control signaling sent by the eNB, where the control signaling is used to indicate use of the second set of tables.

Optionally, referring to FIG. 6, the device may further include a third sending module 61. The third sending module 61 is configured to: if control signaling that is sent by the eNB and used to indicate use of a first set of tables is received, use the first set of tables to report the CQI value to the eNB so that the eNB determines the MCS value according to the first set of tables.

Optionally, the second set of tables corresponding to the first sending module and the first receiving module meets the following conditions:

some entries in the second set of tables are the same as those in the first set of tables;

the number of CQI indexes of a CQI table in the second set of tables is the same as that in the first set of tables; and

the number of MCS indexes of an MCS table in the second set of tables is the same as that in s first set of tables, and the MCS table in the second set of tables includes MCS index entries reserved for HARQ retransmission of a modulation scheme higher than 64QAM.

Optionally, the first sending module determines the CQI value by using the CQI table in the second set of tables, and spectral efficiency in the CQI table in the second set of tables meets the following conditions:

in any modulation scheme whose modulation order is higher than 2, differences between two adjacent spectral efficiency values are approximately equal, where a being approximately equal to b means that an absolute value of a difference between a and b is less than a set value; and

a difference between spectral efficiency values that respectively correspond to two adjacent modulation schemes is less than a difference between any two adjacent spectral efficiency values in a single modulation scheme in the two modulation schemes.

Optionally, the MCS value received by the first receiving module is determined by using the MCS table in the second set of tables, and the MCS table in the second set of tables includes:

all modulation schemes included in the CQI table;

values obtained by performing interpolation for the modulation schemes included in the CQI table; and

values obtained by performing extrapolation for the modulation schemes included in the CQI table; or, values that have the same TBS as that of the modulation schemes included in the CQI table.

Further, the eNB may use the following manner to determine a type of the table to be used:

if an RSRP or an RSRQ is greater than a set value, determining to use the second set of tables; or

if CQI orders reported by the UE and received in a set time are higher than a set order and data is continuously and correctly received, determining to use the second set of tables.

Further, the CQI table in the second set of tables in this embodiment may be specifically shown in Table 3, and the MCS table in the second set of tables may be specifically shown in Table 4 or Table 5.

In this embodiment, a higher-order modulation scheme can be supported by using the second set of tables; and, with the QPSK modulation scheme still included, coverage is sufficiently considered. Compared with the prior art, this embodiment reduces values corresponding to QPSK, which can reduce waste of feedback overhead. By selecting a smaller difference between spectral efficiency values in two adjacent modulation schemes, transition between the two modulation schemes is more stable. The corresponding value is obtained for the higher-order modulation scheme in an equal-spectral-efficiency manner, which can improve system performance smoothly.

Persons of ordinary skill in the art may understand that all or a part of the steps of the method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program runs, the steps of the method embodiments are performed. The foregoing storage medium includes: any medium that can store program code, such as a ROM, a RAM, a magnetic disk, or an optical disc.

Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present invention, other than limiting the present invention. Although the present invention is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the foregoing embodiments, or make equivalent substitutions to some or all the technical features thereof, without departing from the spirit and scope of the technical solutions of the embodiments of the present invention. 

What is claimed is:
 1. An information transmission method, comprising: sending, by a user equipment (UE), control signaling to an eNodeB (eNB), wherein the sent control signaling is used to indicate that the UE supports a second set of tables including a second modulation and coding scheme (MCS) table and a second channel quality indicator (CQI) table, wherein a modulation scheme that can be supported by the second set of tables is higher than 64QAM, wherein the UE also supports a first set of tables including a first MCS table different from the second MCS table and a first CQI table different from the second CQI table; receiving, by the UE, control signaling sent by the eNB, wherein the received control signaling is used to indicate use of the second set of tables; determining, by the UE, a CQI value by using the second CQI table; reporting, by the UE, the CQI value to the eNB, wherein the CQI value is for the eNB to determine an MCS value according to the CQI value; receiving, by the UE, the MCS value sent by the eNB; and receiving, by the UE, physical downlink shared channel (PDSCH) data according to the MCS value.
 2. The method according to claim 1, wherein: some entries in the second set of tables are the same as those in the first set of tables; the number of CQI indexes of the second CQI table is the same as in the first CQI table; and the number of MCS indexes of the second MCS table is the same as in the first MCS table, and the second MCS table comprises MCS index entries reserved for hybrid automatic repeat request (HARQ) retransmission of a modulation scheme higher than 64QAM.
 3. The method according to claim 2, wherein spectral efficiency in the second CQI table meets the following condition: in any modulation scheme whose modulation order is higher than 2, differences between two adjacent spectral efficiency values are approximately equal, wherein a being approximately equal to b means that an absolute value of a difference between a and b is less than a set value.
 4. The method according to claim 3, wherein the second MCS table comprises: all modulation schemes comprised in the CQI table; and values obtained by performing interpolation for the modulation schemes comprised in the CQI table.
 5. The method according to claim 4, wherein the second MCS table includes at least 5 values corresponding to quadrature phase shift keying (QPSK).
 6. The method according to claim 3, wherein the set value is 0.2.
 7. The method according to claim 1, wherein the number of CQI indexes in the second CQI table is the same as in the first CQI table, and the number of MCS indexes in the second MCS table is the same as in the first MCS table.
 8. The method according to claim 7, wherein 4 indices are required in reserved part of the MCS table.
 9. The method according to claim 1, wherein the number of QPSK modulation schemes is less than the number of QPSK modulation schemes used in the related art.
 10. The method according to claim 1, wherein the modulation scheme that can be supported by the second set of tables is 256QAM.
 11. An information transmission device, comprising: a second sending module, configured to send control signaling to an eNodeB (eNB), wherein the sent control signaling is used to indicate that the device supports a second set of tables including a second modulation and coding scheme (MCS) table and a second channel quality indicator (CQI) table, wherein a modulation scheme that can be supported by the second set of tables is higher than 64QAM, and wherein the device also supports a first set of tables including a first MCS table different from the second MCS table and a first CQI table different from the second CQI table; a third receiving module, configured to receive control signaling sent by the eNB, wherein the received control signaling is used to indicate use of the second set of tables; a first sending module, configured to determine a CQI value by using the second CQI table, and report the CQI value to the eNB, wherein the CQI value is for the eNB to determine an MCS value according to the CQI values; a first receiving module, configured to receive the MCS value sent by the eNB; and a second receiving module, configured to receive physical downlink shared channel (PDSCH) data according to the MCS value.
 12. The device according to claim 11, wherein the second set of tables corresponding to the first sending module and the first receiving module meets the following conditions: some entries in the second set of tables are the same as those in the first set of tables; the number of CQI indexes of the second CQI table is the same as in the first CQI table; and the number of MCS indexes of the second MCS table is the same as in the first CQI table, and the second MCS table comprises MCS index entries reserved for hybrid automatic repeat request (HARQ) retransmission of a modulation scheme higher than 64QAM.
 13. The device according to claim 12, wherein spectral efficiency in the second CQI table meets the following condition: in any modulation scheme whose modulation order is higher than 2, differences between two adjacent spectral efficiency values are approximately equal, wherein a being approximately equal to b means that an absolute value of a difference between a and b is less than a set value.
 14. The device according to claim 12, wherein the set value is 0.2.
 15. The device according to claim 13, wherein the MCS value received by the first receiving module is determined by using the second MCS table, and the second MCS table comprises: all modulation schemes comprised in the CQI table; and values obtained by performing interpolation for the modulation schemes comprised in the CQI table.
 16. The device according to claim 15, wherein the second MCS table includes at least 5 values corresponding to quadrature phase shift keying (QPSK).
 17. The device according to claim 11, wherein the second set of tables corresponding to the first sending module and the first receiving module meets the following conditions: the number of CQI indexes in the second CQI table is the same as in the first CQI table; and the number of MCS indexes in the second MCS table is the same as in the first MCS table.
 18. The device according to claim 11, wherein: 4 indices are required in reserved part of the MCS table; and/or the modulation scheme that can be supported by the second set of tables is 256QAM; and/or the number of QPSK modulation schemes is less than the number of QPSK modulation schemes used in the related art. 